Base for an aquarium filter



FIG. 1 is a top plan view of a base for an aquarium filter showing mynew design;

FIG. 2 is a front elevation view of the base;

FIG. 3 is a rear elevation view of the filter base; and,

FIG. 4 is a right side elevation view of the base, a left side elevationview being a mirror image of FIG. 4.

The bottom of the base embodies no design features and is not shown.

The ornamental design for base for an aquarium filter, as shown anddescribed.